Understanding Variables and Constants in Experiments

The video tutorial for seventh graders introduces lesson two, focusing on key scientific concepts such as variables, constants, independent and dependent variables, and the importance of repeated trials. The teacher explains these concepts with examples, emphasizing the need for understanding the differences between variables and constants. The tutorial also highlights the significance of repeated trials in scientific investigations to ensure valid data. Students are encouraged to apply these concepts in their investigations and assignments.

What is the main difference between variables and constants in an experiment?

• Variables are controlled, constants are not.

• Variables are always dependent, constants are independent.

• Variables change, while constants remain the same.

• Variables are always numerical, constants are not.

In an experiment to test plant growth, which of the following could be a variable?

• The type of soil used for all plants.

• The type of plant species.

• The amount of sunlight each plant receives.

• The brand of fertilizer used.

Which of the following is an example of a constant in an experiment?

• The temperature of the room changes daily.

• The time of day the experiment is conducted changes.

• The amount of water given to each plant is the same.

• The type of music played in the background varies.

Which of the following is NOT a characteristic of a constant?

• It remains unchanged during the experiment.

• It is manipulated by the experimenter.

• It provides a stable environment for the experiment.

• It helps in comparing the effects of variables.

What is an independent variable in an experiment?

• A variable that is dependent on the outcome of the experiment.

• A variable that is kept constant throughout the experiment.

• A variable that is purposefully changed or manipulated.

• A variable that changes in response to another variable.

Which of the following best describes a dependent variable?

• It is manipulated by the experimenter.

• It changes in response to the independent variable.

• It remains constant throughout the experiment.

• It is not measured during the experiment.

In the context of experiments, what does it mean if a variable is 'dependent'?

• It is the main focus of the experiment.

• It is controlled by the experimenter.

• It remains unchanged throughout the experiment.

• It changes in response to another variable.

What is the role of an independent variable in an experiment?

• It is the outcome measured by the experimenter.

• It remains constant to provide a control.

• It is the variable that is purposefully changed.

• It is the variable that responds to changes.

Why are repeated trials important in an experiment?

• To increase the number of variables tested.

• To ensure the experiment is completed quickly.

• To reduce the number of constants in the experiment.

• To confirm the results are consistent and reliable.

What could be a reason for conducting repeated trials in an experiment?

• To get different results each time.

• To ensure the data collected is valid.

• To test more variables at once.

• To change the hypothesis frequently.